bonta



(No Model.)

WITNESSES:

Mid?

Q V 2 SheetS- -Sh'eet 1. J. W. BONTA.

TELEPHONE TRANSMITTER.

Patented July 5,1887.

2 Sheets-Shet 2.

(No Model.)

J. W. EON-TA;

TELEPHONE TRANSMITTER.

No. 365,781. Patented July 5; [1887;

. z J H 1 a J & m E a \M/ a INVENTOR/ WTTORNEY I WITNESSES" UNITEDSTATES PATENT OFFICE.

JAMES \V. BONTA, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE AMERICANNATIONAL TELEPHONE COMPANY, OF NEYV YORK.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 365,781, dated July 5,1887.

Application filed October 21, 1886.

To all whom it may concern.-

Be it known that I, JAMES W. BONTA, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, haveinvented certain new and useful Improvements inTelephonic Transmitters, ofwhich the following is a specification. Myinvention has relation to telephonic transmitters of the form having aseries of contacting electrodes and separate batteries and inductoriumsfor each pair or group of contacting clectrodes,the secondaries of allthe inductoriunis beingincluded in a common linecireuit, whereby theaction of the different or I 5 separate primariessimultaneouslyinducecurrents in the secondary of the separate inductoriums to produce asingle working-current equal to the sum of the potentials of theseparately-induced currents.

Herctofore in this form of instrument each group or pairof contactingelectrodes is provided with separate'adjusting devices for varying theinitial contact-pressure of the same. I have found that when each groupor pair of contacting electrodes is separately adjusted it is impossibleto give to each group or pair the same contact-pressure, and thecontact'pressure of one or more of them varies from that of the others,and if great care be not exercised in making the adjustments thecontact-pressure of all ofthem will be different. This variation incontact-pressure of the groups or pairs of contacting electrodessubjects different parts of the diaphragm to different degrees of press5 ure when inaction, so that its action is not uniform throughout itsarea and unequal impulses are produced in the separate inductoriums.

My invention has for its object to avoid the 40 above-described results,and this I accomplish by simultaneously adjusting the contact-pressureof all the groups or pairs of electrodes to give to each pair or groupthe same or an equal contact-pressure, whereby the action of 5 thediaphragm produces equal current-impulsesin all the inductoriums foraugmenting or intensifying the secondary or working current for theline.

My invention accordingly consists of a tele- 5o phonic transmitterhaving a number of sepa- Serial No. 216,799. (No model.)

rate contacting electrodes, each pair or group of contacting electrodeshaving a separate battery-circnit, including the primary of separateinductoriums, the secondary ofwhich is apart of or included in the line,and adjusting mechanism for simultaneously varying the contactpressureof all thepai rs or groups of the coir tacting electrodes equally, ashereinafter more fully described and claimed.

In the drawings I have shown my invention applied to the form oftelephonic transmitter shown and described in United States Patentgranted to me on the 5th day of January, 1885, and numbered 383,816, orthat form wherein a rolling or loose electrode on an inclined table 6has contaet'with the diaphragm oran electrode thereon, and in which-Figure 1 is a verticalsection of the transmitter. Fig. 2 is a rear Viewof electrodes, i11- clined tables or blocks, adjusting mechanism, 0diaphragm-inductoriums, and circuit-connections; and Fig. 3 is avertical section showing modification of construction of parts of thetransmitter.

While I have shown the abovedescribed 7 5 form of transmitter, I do notconfine myself thereto, as my improvements are applicable to any form oftransmitter having multiple contacts.

A represents a transmittercasin g having removable cap (0, provided withmouth-piece a and diaphragm B, with or without elect-rode b,

0 represents the inclined table, of carbon or nietahgrooved orotherwise, as desired. Upon the table 0 is a rolling or loose electrode,D. Two or more of the electrodes b are secured to the diaphragm,and acorresponding number of electrodes D and tables 0 are provided forelectrodes 1), to obtain multiple contacts or pairs of electrodes, eachof which is in circuit 0 with the primary 1 of a separate inductoriu m,

I, each of which primaricsincludes a separate battery, 2, and thesecondaries 3 of all the inductoriums are in circuit with asingleorcommon line, 4, as more plainly shown in Fig. 2, 5 so that each pair ofelectrodes, when operated simultaneously, varies or impulses a separatebattery-current and these separate battery-current impulsessimultaneously induce separate currents in the secondaries of separateinduc- IOO toriums to produce one working or line current of a potentialequal to the sum of all the separately-induced currents. Each pair ofelectrodes, as well as each block or plate therefor, is insulated fromall the others, and the circuit-connections between the primaries andelectrodes may be provided for as shown or as desired.

In Figs. 1 and 2 I have shown six pairs of electrodes arranged in tworows or series, one above the other. I

The platforms G for the blocks are pivoted to casing-standards g, andhave an adj usting-rod, h, suitably made and held in its adjustedposition by a set-screw, h. By moving bar h up or down, all the blocksare simultaneously adjusted as to their inclination, and the degree ofcontact-pressure for all the pairs of the electrodes is correspondinglyvaried, so that the contact-pressure for the electrodes is the same orequal throughout both series or rows of same. a

In Fig. 3 only one row of three pairs of contacts or electrodes isshown; but the number may be varied as desired, and the tables 0 orplatforms G have a single adjusting screw, h.

What I claim is- 1. A telephonic transmitter having multiple or a numberof separate pairs of electrodes, separate inductoriums for each pair ofelectrodes, separate batteries in the primaries of pairs of contactingelectrodes, substantially as set forth.

2. Atelephonictransmitterhavinganumber of separate pairs or groups ofcontacting electrodes, a single adjusting device for simultaneouslyvarying their initial contact pressure, separate inductoriums for eachpair of contacts or electrodes, and a separate battery in the primary ofeach inductorium, the secondaries of all of which are in circuit withthe line.

3. In combination with a diaphragm having a number of loose or rollingelectrodes in contact therewith,separate circuit-connections for eachelectrode with the primaries of sepa rate inductoriums, a separatebattery in the primary of each inductorium, the secondaries of whicharein circuit with the line,and an adj usting device for simultaneouslyand equally varying the initial contact-pressure of the contactingelectrodes, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES W. BONTA.

Witnesses:

S. J. VAN Smvonmv, J. DANIEL EBY.

